From owner-freebsd-current Sat Nov 18 7:24: 4 2000 Delivered-To: freebsd-current@freebsd.org Received: from mharnois.workgroup.net (c1030098-a.wtrlo1.ia.home.com [24.11.39.39]) by hub.freebsd.org (Postfix) with ESMTP id 1C7AD37B479; Sat, 18 Nov 2000 07:24:02 -0800 (PST) Received: (from mdharnois@localhost) by mharnois.workgroup.net (8.11.1/8.11.1) id eAIFMlN03169; Sat, 18 Nov 2000 09:22:47 -0600 (CST) (envelope-from mdharnois@home.com) X-Authentication-Warning: mharnois.workgroup.net: mdharnois set sender to mdharnois@home.com using -f To: John Baldwin Cc: Sheldon Hearn , current@FreeBSD.ORG, Valentin Chopov , Boris Popov , Soren Schmidt , "Steven E. Ames" , Alfred Perlstein Subject: Re: CURRENT is freezing again ... Keywords: debugger,pci,mutexes References: From: Michael Harnois Date: 18 Nov 2000 09:22:47 -0600 In-Reply-To: Message-ID: <86y9yhl2yg.fsf@mharnois.workgroup.net> Lines: 26 User-Agent: Gnus/5.0808 (Gnus v5.8.8) XEmacs/21.2 (Pan) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Fri, 17 Nov 2000 10:30:02 -0800 (PST), John Baldwin said: > what the WITNESS code does is perform extra checks on mutex > enter's and exit's to ensure that we aren't handling mutexes in > such a way that a deadlock is possible. Thus, it verifies that > you don't grab mutexes out of order, or that you don't grab > sleep mutexes with interrupts disabled, etc. Is this code meaningful on UP machines? Having been a victim of these seemingly random freezes since SMPng started, as others have noted, I decided to compile it in earlier this week. Twice now I've been dumped into the debugger with this output: lock order reversal 1st dc0 last acquired @ ../../pci/if_dc.c:2717 2nd 0xc0acdb3c dc1 @ ../../pci/if_dc.c: 2717 3rd 0xc0acab3c dc0 @ ../../pci/if_dc.c: 2929 Debugger ("witness_enter") Stopped at Debugger+0x39: movb $0, in.Debugger.639 -- Michael D. Harnois, Redeemer Lutheran Church, Washburn, IA mdharnois@home.com aa0bt@aa0bt.ampr.org The atheist staring from the attic window is often nearer to God than the believer caught up in his own false image of God. -- Martin Buber To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message